Learning Java - Chapter 12 : Java

It can be useful in designing a user interface to control the look of the cursor according to the current position and/or processing going on.

The Component class includes the setCursor() method that can change the cursor icon when it is above a particular component.

CursorTestApplet

import javax.swing.*;
import java.awt.*;

/** Demonstrate the different cursor styles.**/
public class CursorTestApplet extends JApplet
{
  CursorPanel fCursorPanel = null;

  /** Build the interface.**/
  public void init () {
    Container content_pane = getContentPane ();

    // Create an instance of a JPanel sub-class
    fCursorPanel = new CursorPanel ();

    // And add one or more panels to the JApplet panel.
    content_pane.add (fCursorPanel);
  }
} // class CursorTestApplet

/** A JPanel subclass showing the different cursors.**/
class CursorPanel extends JPanel
{
  CursorPanel () {

    setLayout (new GridLayout (7,2));

    JButton bt = new JButton ("Default");
    bt.setCursor (new Cursor (Cursor.DEFAULT_CURSOR));
    add (bt);

    bt = new JButton ("Busy");
    bt.setCursor (new Cursor (Cursor.WAIT_CURSOR));
    add (bt);

    bt = new JButton ("Hand");
    bt.setCursor (new Cursor (Cursor.HAND_CURSOR));
    add (bt);

    bt = new JButton ("Text");
    bt.setCursor (new Cursor (Cursor.TEXT_CURSOR));
    add (bt);

    bt = new JButton ("CrossHair");
    bt.setCursor (new Cursor (Cursor.CROSSHAIR_CURSOR));
    add (bt);

    bt = new JButton ("Move");
    bt.setCursor (new Cursor (Cursor.MOVE_CURSOR));
    add (bt);

    bt = new JButton ("East Resize");
    bt.setCursor (new Cursor (Cursor.E_RESIZE_CURSOR));
    add (bt);

    bt = new JButton ("North Resize");
    bt.setCursor (new Cursor (Cursor.N_RESIZE_CURSOR));
    add (bt);

    bt = new JButton ("West Resize");
    bt.setCursor (new Cursor (Cursor.W_RESIZE_CURSOR));
    add (bt);

    bt = new JButton ("South Resize");
    bt.setCursor (new Cursor (Cursor.S_RESIZE_CURSOR));
    add (bt);

    bt = new JButton ("NorthEast Resize");
    bt.setCursor (new Cursor (Cursor.NE_RESIZE_CURSOR));
    add (bt);

    bt = new JButton ("NorthWest Resize");
    bt.setCursor (new Cursor (Cursor.NW_RESIZE_CURSOR));
    add (bt);

    bt = new JButton ("SouthWest Resize");
    bt.setCursor (new Cursor (Cursor.SW_RESIZE_CURSOR));
    add (bt);

    bt = new JButton ("SouthEast Resize");
    bt.setCursor (new Cursor (Cursor.SE_RESIZE_CURSOR));
    add (bt);
  } // ctor

} // class CursorPanel

With Java 1.2 came the ability to create custom cursor icons. The method

createCustomCursor(Image cursor, Point hotSpot, String name)

in the java.awt.Toolkit class, you pass the image for the cursor. The second argument specifies the so-called hotspot that sets the X, Y coordinates, relative to the top left corner of the image, of the pixel where the click occurs. For example, this would specify the end of the tip of an arrow cursor. The last argument provides the name of the cursor for the Java Accessibility system to use. (The Accessibility framework, not discussed here, provides for enhancements for handicapped users.)